On Fri, Mar 05, 2021 at 06:00:04PM +0100, Eric Botcazou wrote:
> > Here, when substituting still-dependent args into an alias template, we see
> > a non-const type because the default argument is non-const, and is not a
> > template parm object because it's still dependent.
> >
> > Tested x86_64-pc-linux-gnu, applying to trunk.
> >
> > gcc/cp/ChangeLog:
> >
> > PR c++/98810
> > * pt.c (tsubst_copy) [VIEW_CONVERT_EXPR]: Add const
> > to a class non-type template argument that needs it.
> >
> > gcc/testsuite/ChangeLog:
> >
> > PR c++/98810
> > * g++.dg/cpp2a/nontype-class-defarg1.C: New test.
>
> This apparently went down to the 9 branch as well and introduced:
>
> Running /home/eric/cvs/gcc-9/gcc/testsuite/g++.dg/dg.exp ...
> ERROR: g++.dg/cpp2a/nontype-class-defarg1.C -std=c++98: syntax error in
> target selector "target c++20" for " dg-do 2 compile { target c++20 } "
>
> ERROR: g++.dg/cpp2a/nontype-class-defarg1.C -std=c++98: syntax error in
> target selector "target c++20" for " dg-do 2 compile { target c++20 } "
> ERROR: g++.dg/cpp2a/nontype-class-defarg1.C -std=c++14: syntax error in
> target selector "target c++20" for " dg-do 2 compile { target c++20 } "
>
> ERROR: g++.dg/cpp2a/nontype-class-defarg1.C -std=c++14: syntax error in
> target selector "target c++20" for " dg-do 2 compile { target c++20 } "
> ERROR: g++.dg/cpp2a/nontype-class-defarg1.C -std=c++17: syntax error in
> target selector "target c++20" for " dg-do 2 compile { target c++20 } "
>
> ERROR: g++.dg/cpp2a/nontype-class-defarg1.C -std=c++17: syntax error in
> target selector "target c++20" for " dg-do 2 compile { target c++20 } "
>
> On the contrary, the 10 branch is a in good shape.
Fixed:
GCC 9 doesn't have the "c++20" target yet.
* g++.dg/cpp2a/nontype-class-defarg1.C: Use target c++2a.
---
gcc/testsuite/g++.dg/cpp2a/nontype-class-defarg1.C | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/gcc/testsuite/g++.dg/cpp2a/nontype-class-defarg1.C
b/gcc/testsuite/g++.dg/cpp2a/nontype-class-defarg1.C
index ddd64d6165b..4e7261a203c 100644
--- a/gcc/testsuite/g++.dg/cpp2a/nontype-class-defarg1.C
+++ b/gcc/testsuite/g++.dg/cpp2a/nontype-class-defarg1.C
@@ -1,5 +1,5 @@
// PR c++/98810
-// { dg-do compile { target c++20 } }
+// { dg-do compile { target c++2a } }
template struct a {};
template s = a {}> using b = a ;
base-commit: a5a7cdcaa0c29ee547c41d24f495e9694a6fe7f1
--
2.29.2
